The present invention relates to a portable lighting instrument suitable for use, in taking off and landing of a helicopter on a temporary heliport safely at night at the urgent time or the like, with emergency "a boundary lamp" or "a boundary guide lamp" in the heliport.
In the place for taking off and landing of a helicopter, there are some kinds and natures determined under laws and ordinances, which are represented by a name peculiar thereto. However, the respective places are obliged to provide a lighting system necessary in taking off and landing of a helicopter. For example, it is necessary for places called "an urgent taking off and landing place" and "an urgent rescue space" to install at least "a heliport lighthouse" whose light is an alternate flash of white or an alternate flash of white and green, "a wind lamp" whose light is white, "a boundary guide lamp" whose light is green, and "a boundary lamp" whose light is white or yellow. Further, in "a taking off and landing place outside an airport, it is requested to install various kinds of lighting instruments in accordance with "an urgent taking off and landing place" or "an urgent rescue space" according to the using object on all such occasions.
The above-described various kinds of lighting instruments presently used include lamps such as a xenon lamp, a halogen lamp and the like, and these lamps are fixedly mounted in a fixed position. In order that lighting and lighting-out may be controlled by manually operating a control unit available nearby or operating a control unit placed in a remote center, the lighting instruments are connected with the control unit by necessary wiring. Installing operation accompanied by wiring is cumbersome, and obviously there lacks in conformity at the time of emergency.
Recently, there has been proposed a lighting system for a helicopter taking off and landing place in which with respect to the "a heliport lighthouse", "a wind lamp" and "a landing area lighting lamp", a generator with a lamp such as a halogen lamp is separately installed, and with respect to the "a boundary lamp" and "a boundary guide lamp", a lamp with a charging type battery is installed to thereby eliminate the necessity of a wiring. However, since a lamp of large consuming power is involved, a generator and a battery having a large capacity are necessary, and as a result, cost for apparatuses increases. Further, since noises and exhaust gases are generated when the engine is operated in addition to the cumbersome that the engine of a generator should be started and prepared in advance, there has posed a problem of exerting an unfavorable effect on the peripheral environment. In the case of a charging type lamp, since long charging time for 6 to 8 hours is necessary, precharging is necessary, and the lighting time also ought to be relatively short. A secondary battery such as a lead battery is used, and when the battery is left for a long period of time, it becomes naturally discharged not to obtain necessary and sufficient voltage, which is therefore possibly be useless at the time of emergency. Even if an attempt is made to use the battery again after discharge, it takes a long time for charging, and there lacks in conformity.
An attempt of using a light emitting diode as a light source for general lighting has been made so far, but application thereof to a lighting system for a helicopter taking off and landing has not yet been succeeded.